Pelorus



March 26, 1946a R. o. BURGESS ETAL 7,

' PELORUS Filed Dec. 22 1941 2 Sheets-Sheet 1 INVENTORS lzober-fafiuryess Z, I BYEdmrUCICrai March 26,1946. HAL 2,397,125

PELORUS Filed Dec. 22, 1941 2 Sheets-Sheet'Z INVENTORS Robert 0. Burgess 7.

Patented Mar. 26, 1946 2,397,125 PELORUS Robert 0. Burgess, Arlington, Va., and Edward C. Craig, United States Navy Application December 22, 1941, Serial No. 423,960

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'70 0. G. 757) 6 Claims.

This invention relates to instruments for measuring horizontal angles, and it has a particular relation to a pelorus used on shipboard for determining the angle between a line of sight and the longitudinal axis of the vessel,

One of the objects of the present invention is the provision of a pelorus of the character described which embodies a dial or compass card having stencil indicia and a self-luminous screen of relatively short extent located beneath the dial and movable with the sighting means of the instrument to at times illuminate selected indicia of the dial with a minimum of light dispersion.

Another object of the invention is the provision of a pelorus in which electric illumination may be substituted for the self-luminous means when necessary or desired without displaying an undesired amount of light.

Still another object of the invention is the provision of apelorus adapted to be mounted on the deck of a vessel and adapted to be connected in a suitable manner with the data computer located remote therefrom and employed in automatically setting the gyro directing instrumentalities of a torpedo.

A further object of the invention is the provision-ofa pelorus equipped with night sighting means and audible means for indicating theangle onsight when the vessel is operating under blackout conditions.

I'With these and other objects in view, as well as other advantages that may be incident to the use of the improvements, the invention consists int-he parts and combinations thereof hereinafter set forth and claimed, with the understanding that the several necessaryelements-constituting the same may be varied in proportion and ar- .rangement without departing from the nature andscope of the invention, as defined in the appended claims,

:In order to make the invention more clearly understood, there are shown in the accompanying drawings, means for carrying the invention into practical use, without limiting the improvements in their useful application to 'the;particular construction, which, for the purpose of explanation, have been made the subject of illustration.

.Inthe accompanying drawings: Fig. 1 is a plan view of a pelorus constructed .in accordance with the invention;

Fig. 2..is .an elevational view of the structure shown .in Fig. 1 with the sighting binoculars in position thereon;

Fig. 3 is a vertical sectional view taken on line 3-3 of Fig. 2;

Fig. 4 is a side elevational'view of the structureshown in Fig. 2; and

Fig. 5 is an enlarged fragmentary longitudinal sectional view of the luminous screen portionof the alidade.

Referring to the drawings, a pelorus embody-.

ing the invention is shown as comprising a central hub It adapted to be mounted in a machine gun socket on the bridge rail of a submarine and is formed with an axial bore H (Fig. 3). A spider I2 is secured to the upper end of'the hub it by screws l3 and forms the support for aspacing ring it and an annular dial l5 whichare secured together by round headed rivets :lii. These rivets are spaced ten degrees apart so that they may be located in the dark by sense of touch, and correspond in location to ten degree markings 11 stencilled in the dial l5. The outer circumferential surface of the spacing ring l4 may also be graduated if so desired, as indicated at l8.

Cooperating with the dial I5 is an alidade l9 in .the form of a diametrically extended bar secured at its middle to a sleeve 20 which isrotatably mounted in the bore H of the hub l0 and which is held against displacement therefrom by a retaining nut 2| having a knurled circumferential surface, and a lock washer 22 secured to the sleeve. One end of the alidade l8 extends beneath the dial ring l5 and is provided with a recess 23 for receiving a self-luminous capsule 24, the light from which passes upwardly through the stencilled indicia l1 beneath which the capsule may, at the time, be positioned, This capsule comprises a lower receptacle'2-5 of transparent thermo-plastic material for containing the self-luminous body and an upper cover 26 of similar transparent material united therewith and sealed around their edges. A bracket 2! is fixed to the alidadein overhanging relation to the dial ring I5 and capsule 24 and is formed with a rectangular opening 28 having a transparent plastic member 29 seated therein forming .a window through which the illuminated indiciaof the dial may be observed. The transparentmember 29 is provided with a lubber line 30 for cooperation with the dial l5. A cover plate M is hingedto the bracketZl in order that the window 3!] may be closed to obscure all illumination when the instrument is not actually being read but which may be opened momentarily when it may become necessary to make a reading,

The indicia of the dial ring may be illuminated p uter located at the independently of the self-luminous capsule 24 when so desired by means of an electric lamp 32 of the flashlight type, which may be inserted in the sleeve 20. The light from the lamp is transmitted through a passageway 33 formed in the alidade l9 and through the transparent cover plate 26 of the capsule and the stencilled indicia I! of the dial.

The lamp 32 is held in position 7 by a collar 34 secured to thebattery container 35 its angular position automatically to a torpedo station. r 7

By means of the type of illumination herein- 7 above described the fire control officer may ob- V serve and read the instrument witha minimum of effect .upon the eye focus such as may undesirably affect or impair his vision in total darkness. It will be understood that the above description and accompanying drawings comprehend only the general and preferred embodiment of the inven tion,. and that various changes in construction,

Mounted on or cast integrally with the alidade I I9 intermediate its ends and movable therewith is-a pair of vertically extending spaced brackets 39 between the upper ends of which a binocular rest or carriage 40 is pivotally mounted, as at 4|, 7 for tilting movement about a transverse horizontal axis. This rest is provided with a tapered opening 42 intermediate its ends for receiving'a wedge shaped lug 43 formed on a binocular holder or cradle 44 and with depending counterweighted arms 45 for balancing the weight of a pair f binoculars 46. The tilting movement of the rest 40 is limited by means of pins 47 fixed in the],

brackets 39 and extending into arcuate slots 48' These binoculars are 7 formed, in" the arms. 45.

pivotally mounted'on a pin 49 journalled inthe holder 44 'for tilting movement about a longitudinally extending axis. The alidade l9 and parts carried thereby may be turned about'its vertical axis in order to sight the instrument, by

proportion and arrangement of the parts may be made Within the scope of the appended claims without sacrificing any of the advantages of the invention.

The invention described herein maybe manufactured and used by or for the Government of the United States of .America for governmental purposes without the payment of any royalties thereon or therefor. 7 7

.Having thussetforth and-disclosed the nature of this invention, what is claimed is: V I

1. A pelorus for use in determining the angle defined by the intersection of a line of sight with the fore and aft axis of;a vessel; comprising a stationary dial plate having stencil apertures therethrough defining dial indicia of'relativelyj large extent, an alidade mounted'on one side of said dial plate for rotation thereabout, sighting means carried by said alidade, a self-luminous screen of relatively small extent carried by and movable with said alidade on the other, side of said dial plate for illuminating selected indicia, a transparent window carried by said alidade and havinga lubber linev thereon for cooperation with the illuminated indicia, and a closure member for said window adapted'to be opened orclosed to selectively render visible or'to obscure from view 7 means of handles 50 fixed to the brackets 39.

Thus, it will'be seen that this pivotal movement of the holder 44 and the pivotal movement of the rest 40 provide a universal mounting forthe bion a target rother object notwithstanding the pitch and roll of the'vessel. A pair of vertically extending pins 5| are preferably provided on the rest 40 for engagement with registering openings forniedin the holder 44; Thigconstruction in- V sures a firm mounting forthe binoculars when in' use and yet permits of the quick removal of the same when the submarine submerges, the re mainder of the pelorus structure remaining in place during submerged activities This aifords an instrument ready for immediate use upon sur- 7 facing; I p ,V

The touch system provided by the round headed 'l nocula'rsg4 6 such as will permit a sight to be held or rivets l6 fordetermining the angle of the alidade in the dark is'supplemented by an audible system provided byaspring pressed detent 52 carried by I "the alidade for engagement with a series of circularly arranged drill holes or notches 53 provided 7 in a disc 54 secured to the'spider I2.

fl'he rotatable parts" of .the hereinaboveIde-V scribed instrument which include'rthe sleeve 20' and nut ZJlmay be connected beneath the bridge rail with suitable electrical means, such as a selfsynchronous motor system, with the datarcomwithin the hull.

From the foregoing display of an unnecessary and undesired amount it will be apparent that'at very simple and turdy pelorus' is provided which may efficiently be employed at night withoutthe' torpedo directing station 7 r of light, which may be held onra line of sight 7 with accuracy and which may be used to transmit the illuminated indicia of said dial plate.

defined by the intersection of a line of sight with the fore and aft axis of a vessel, comprising a stationary dial ring having stencil apertures therethrough' defining dial indicia of relatively' large extent, an alidade mounted for rotation above said dial ring and having one endthereof extending beneath saiddial ring and having a recess thereingsighting means carried by said, alidade,

a self-luminous capsulew disposed within there-, 7

cess in said alidade and beneath said dial ring for illuminating selected indicia, a transparent window carried by saidalidade and having alllbber line thereon for cooperationwith the illuminated indicia, and a closure member for said window adapted to be opened and closed'to selectively f render visible orto obscure from minatedindicia of said dial plate. a

' 3. A pelorus for use in determining theangle defined by the intersection of a, line of sight with the fore and aft axis of a vessel, comprising a stationary dial .plate' having stencil apertures therethrough defining dial indicia of relatively large extent, an alidade. mounted tor rotation ,7

above said dial plate, sighting'means carried by said alidade, a self-luminous screen of relatively small extent carried by said alidade beneath said j dial plate for illuminating selected indicia, a p A transparent window carried by said alidade and having a lubber line'thereon for cooperation with the illuminatedindicia'a closure member for said 7 window adapted to be opened or closed to selectively rendervisible or to obsc'ureirom view the illuminated indicia of said dial plate, and audible means for indicating'said angle when said'indicia is obscured.

2. .Apelorus for use in determining th angle 7 view the illu- V 4. A pelorus for use in determining the angle defined by the intersection of a line of sight with the fore and aft axis of a vessel, comprising a stationary dial plate having stencil apertures therethrough defining dial indicia of relatively large extent, an alidade mounted for rotation above said dial plate, sighting means carried by said alidade, a self-luminous screen of relatively small extent carried by said alidade beneath said dial plate for illuminating selected indicia, a transparent window carried by said alidade and having a lubber line thereon for cooperation with the illuminated indicia, a closure member for said window adapted to be opened or closed to selectively render visible or to obscure from View the illuminated indicia of said dial plate, and means for indicating said angle by sense of touch when said indicia are obscured.

5. A pelorus for use in determining the angle defined by the intersection of a line of sight with the fore and aft axis of a vessel, comprising a stationary dial plate having stencil apertures therethrough defining dial indicia of relatively large extent, an alidade mounted for rotation above said dial plate, a self-luminous screen of relatively small extent carried by said alidade beneath said dial plate for illuminating selected indicia, a transparent window carried by said alidade and having a lubber line thereon for cooperation with the illuminated indicia, a closure member for said window adapted. to be opened and closed to selectively render visible or to obscure from View the illuminated indicia of said dial plate, a bracket fixed to said alidade, and'an optical instrument mounted on said bracket for pivotal movement about horizontally disposed transversely extending axes for orienting said indicating means.

6. A pelorus for use in determining the angle defined by the intersection of a line of sight with the fore and aft axis of a vessel, comprising a hub portion adapted to be mounted on the rail of a vessel and having an axial bore therein, a support fixed to said hub, a dial fixed to said support and having stencilled indicia therein, an alidade pivotally mounted in said hub for rotation above said dial and having a. recess formed in one end thereof beneath said dial for containing a self-luminous capsule and a radial passageway establishing communication between said recess and the bore in said hub, and sighting means carried by said alidade, said bore being adapted to receive an electric lamp for transmitting light through said passageway to said recess and thence through said stencilled indicia independently of said selfluminous capsule, said capsule and said lamp being selectively employed to illuminate said stencilled indicia.

, ROBERT O. BURGESS.

EDWARD C. CRAIG. 

